论文标题
在选择性激光融化中的基于ZR的块状金属玻璃中的部分结晶
Partial crystallization in a Zr-based bulk metallic glass in selective laser melting
论文作者
论文摘要
无定形状态的金属作为结构材料有希望，因为它们与缺乏晶粒边界和脱位有关的卓越特性。实现无定形状态需要以高冷却速率淬火，这是常规的尺寸限制的限制，这是弥补尺寸的尺寸，这是弥补尺寸的尺寸限制（am）。 （BMG）合金的临界冷却速率极低，可以在AM中使用。 Recent studies on AM from Zr-based BMGs by selective laser melting(SLM)has proved the possibility of attaining the amorphous state and revealed partial crystallization to be the principal drawback of this process.The present work aims to analyze the conditions for partial crystallization and try to control it by optimizing the process parameters.A comprehensive parametric analysis is accomplished in single-track SLM experiments with Zr-based BMG alloy Vit 106.观察到的微观结构与激光障碍区域中的分析热转移模型估算的温度场和热周期有关。在激光轨道的横截面中，中央明亮的域被确定为重新启动的区域。为重新安装的区域。一个环形的深色较深的结晶区域。扫描速度。似乎在激光器处理溶解在激光器融化之前之前，底物中存在的主要结晶夹杂物。重新恢复区域中的平均冷却速率大大远大于关键冷却速率，因此，预期的均匀核定均可及时地构成晶体的晶体构成，使得晶体构成的晶体构成的构成均匀含量，并在理论上构成了晶体的构成。没有完全溶解
Metals in amorphous state are promising for the use as structural materials due to their superior properties related to the absence of grain boundaries and dislocations.Obtaining the amorphous state requires quenching with a high cooling rate.In conventional technologies,this is the reason for a considerable size limitation hindering application of amorphous alloys.Additive manufacturing (AM) is free of the size limitation.The so-called bulk metallic glass (BMG) alloys have extremely low critical cooling rates and can be used in AM. Recent studies on AM from Zr-based BMGs by selective laser melting(SLM)has proved the possibility of attaining the amorphous state and revealed partial crystallization to be the principal drawback of this process.The present work aims to analyze the conditions for partial crystallization and try to control it by optimizing the process parameters.A comprehensive parametric analysis is accomplished in single-track SLM experiments with Zr-based BMG alloy Vit 106.The observed microstructures are related to the temperature fields and thermal cycles estimated by an analytic heat-transfer model in the laser-impact zone.In the cross section of a laser track,a central bright domain is identified as the remelted zone.An annular darker crystallization zone encircles the remelted zone.The model fits the experimentally obtained dependencies of the remelted zone size versus laser power and scanning speed.It seems that primary crystalline inclusions existing in the substrate before laser processing dissolve at the laser melting.The mean cooling rate in the remelted zone is much greater than the critical cooling rate.Therefore,homogeneous nucleation isn't expected.Nevertheless,the theoretically estimated crystallization times are sufficient for a considerable crystal growth in the heat-affected zone where primary crystalline inclusions and nuclei are not completely dissolved
